河北坝上高原与冀北山地交错带森林群落研究

Studies on the forest communities in the transitional zone between Bashang plateau and Jibei mountainous region

河北坝上高原与冀北山地交错带（简称交错带），地处河北省北部承德市的围场满族蒙古族自治县、隆化县、丰宁满族自治县和张家口市的沽源县、康保县、万全县、崇礼县、赤城县、张北县和尚义县境内，东西长约360—380km，南北宽约100km，总面积为45726km^2。以植物群落的种类组成、外貌和结构以及群落的环境特征为依据，按《中国植被》的植被分类系统，可将该地区的木本群落分为针叶林和落叶阔叶林2个植被类型及16群系。研究表明，交错带是华北地区森林最为丰富的区域，是京津地区的生态屏障，是华北最重要的物种基因库，应严格保护和科学利用。

The transitional zone between the Bashang plateau and the Jibei mountainous region lies in the counties of Weiehang, Longhua and Fengning of Chengde Prefecture and the counties of Guyuan, Kangbao, Wanquan, Chongli, Chicheng, Zhangbei and Shangyi of Zhangjiakou Prefecture. The transitional zone covers an area of 45 726 km^2, with a length of 360 - 380 km from west to east and a width of 100 km from south to north. According to categories, appearances, structures and environmental characteristics of plant communities and in the light of the classification system of China Vegetation, the woody plant communities in the transitional zone may be divided into two vegetation types （the coniferous forest and the deciduous broad-leaved forest） and sixteen plant formations. The study results indicate that the transitional zone is an area in which the forest resource is the most abundant in north China. It is also the ecological barrier for Beijing and Tianjin and the most important gene bank of species in north China. Strict protection measures must be taken and the development must be scientific and reasonable in this transitional zone.